PHYLOGENY OF THE AUSTRALIAN CAMPHOROSMEAE (CHENOPODIACEAE) AND THE TAXONOMIC SIGNIFICANCE OF THE FRUITING PERIANTH

Molecular and morphological data were used to reconstruct the phylogeny of Camphorosmeae (Chenopodiaceae) in Australia, a tribe adapted to and widespread in the temperate arid and semiarid areas of the continent. A total of 71 species, representing nearly half of the species and all 14 currently recognized endemic genera, were sampled. Of seven molecular markers tested (ETS, ITS, the trnL-trnF spacer, the trnP-psaJ spacer, the rpS16 intron, the rpL16 intron, and the trnS-trnG spacer), only the nuclear ETS and ITS provided enough variation for phylogenetic studies in the group. Phylogenetic hypotheses inferred from molecular data do not support the current taxonomy of Camphorosmeae in Australia. Neobassia, Threlkeldia, Osteocarpum, and Enchylaena should be subsumed into the species-rich genera Sclerolaena and Maireana. Of 15 morphological characters, only the fruiting perianth provided some support for the taxonomic implications of the DNA-based phylogeny. Indumentum characters, which were reported to be of taxonomic significance in several groups in Chenopodiaceae, did not provide support for the molecular phylogeny of Camphorosmeae in Australia.